"Our own network was not breached, but rather that of a third party entity," the company said in the statement. "We are still gathering information on the details and are not in a position to provide specifics on the third party involved. Presently, we have no indication that the code disclosure impacts the functionality or security of Symantec's solutions," the statement said.

Symantec spokesman Cris Paden identified the two affected products as Symantec Endpoint Protection 11.0 and Symantec Antivirus 10.2. Both products are targeted at enterprise customer and are more than five years old, Paden said.

"We're taking this extremely seriously, but in terms of a threat, a lot has changed since these codes were developed," Paden said. "We distributed 10 million new signatures in 2010 alone. That gives you an idea of how much these products have morphed since then, when you're talking four and five years."

Symantec is developing a remediation process for enterprise customers who are still using the affected products, Paden noted. Details of the remediation process will be made available in due course, he added.

An Indian hacking group calling itself Lords of Dharmaraja had earlier claimed that it had accessed source code for Symantec's Norton AV products.

A member of the group using the handle "Yama Tough," initially posted several documents on Pastebin and Google+ that purported to be proof that the group had accessed Symantec's source code.

According to Symantec, the initial set of documents posted by the hacking group was not source code. Rather, it was information from a publicly available document from April 1999 defining the API for something called the Definition Generation Service. The document explains how the software is designed to work, but no actual source code was in it, Symantec had noted.

A second set of documents posted by the group, however, did contain segments of Symantec source code for the two enterprise security products, Paden said.

Comments posted by Yama Tough on Google+ and Pastebin suggest that the Symantec information was accessed from an Indian government server. Many governments requires companies such as Symantec to submit their source code for inspection to prove they are not spying on the government.

"As of now we start sharing with all our brothers and followers information from the Indian Militaty (sic) Intelligence servers, so far we have discovered within the Indian Spy Programme (sic) source codes of a dozen software companies which have signed agreements with Indian TANCS programme (sic) and CBI," Yama Tough had said in one comment.

It is still too early to see what impact the code disclosure will have on Symantec and its enterprise customers. Some say that exposure of older source code will likely pose less of a risk because of the fast pace at which security products evolve.

Rob Rachwald, director of security strategies at security vendor Imperva, said there isn't much the hackers can learn from the code that they don't know already.

"The workings of most of the antivirus' algorithms have been studied already by hackers in order to write the malware that defeats them," Rachwald wrote in a blog post Thursday. "A key benefit of having the source code could be in the hands of the competitors," he said.

This is the second time in less than a year that a major security vendor has found itself in the embarrassing position of owning up to a data breach. Last year. RSA disclosed that unknown attackers had accessed source code to its SecurID two-factor authentication technology. The breach prompted widespread concerns about the security of the company's authentication products within government and the private sector.

In Symantec's case, the compromise did not result from a breach of its own servers. Even so, the fallout from the code exposure could be significant for the company, especially if a large number of its enterprise customers are still using the two compromised products.